There are several types of immunoglobulins.

There are five types of immunoglobulins: IgA, IgM, IgD, IgE, and IgG. Among them, IgA is the most abundant immunoglobulin on cell membranes and primarily protects mucosal tissues from pathogen invasion. IgM is predominantly found in the blood and can recognize newly emerging antigens, initiating an immune response against them. IgD functions on the cell surface, enabling cells to identify bacteria. IgE is a special type of immunoglobulin mainly responsible for defending against parasites, reacting to allergens, and neutralizing bacterial toxins. Finally, IgG is the primary serum immunoglobulin, accounting for 90% of all immunoglobulins in the serum. It can bind to bacteria, viruses, and toxins, thereby preventing their spread. Through these specialized immunoglobulins, the body effectively resists invasion by foreign pathogens and maintains health.